1. Field of the Invention
The present invention relates to improvements in a fuel supply apparatus for an internal combustion engine, and more particularly to a fuel supply control apparatus which supplies an adequately controlled mixture of air and fuel to each cylinder.
2. Description of the Prior Art
It is well known that automative vehicles are provided with fuel supply apparatus by which an air-fuel ratio is controlled and supplied to each cylinder. A typical fuel supply apparatus is, for example, disclosed in Japanese Provisional Publication Nos. 55-148932 and 58-23245. Such a fuel supply apparatus is provided with an opening-closing valve in the vicinity of an intake valve of an internal combustion engine. The opening-closing valve is operated to control an intake air flow rate fed to a combustion chamber of the engine to improve the pumping loss of the engine.
On the other hand, to improve the irregularity of the air-fuel ratio among the cylinders of the engine, a fuel supply apparatus is disclosed in Japanese Provisional Publication No. 62-101868. Such fuel supply apparatus includes a pressure sensor which is installed proximate each intake port to respectively detect each intake pressure. The fuel supply amount to each cylinder is corrected in accordance with the detected intake pressure. However, although the irregularity of the air-fuel ratio among the cylinders is improved by the installation of such a pressure sensor to each cylinder, the production cost of the engine is largely raised.